By Martin Patience
BBC News, Jerusalem
After six years in the political wilderness, Ehud Barak has romped back to the centre of the Israeli political stage.
Mr Barak has promised to re-establish Israel's military power
The former prime minister's victory in the Labour leadership contest means that once again he is a big political player.
The Labour leadership came up for grabs after its former leader Amir Peretz failed to secure his party's re-election.
Mr Peretz, defence minister in the governing coalition, came under sustained criticism from his own party and the country at large following the war in Lebanon in 2006.
Now, Mr Barak has stepped into the breach and promised to rebuild trust in a deeply unpopular Israeli government.
"Today brings the long journey towards bringing back level-headed, responsible and experienced leadership to the state of Israel," he said.
The Labour is the second-largest party in the current coalition government led by Ehud Olmert.
Defence minister job?
During the leadership campaign, Mr Barak vowed to pull the party out of the coalition if Mr Olmert remained prime minister.
Mr Olmert has suffered from dismal approval ratings following his perceived bungling of the military campaign in Lebanon.
Mr Barak infuriated many of his countrymen by offering East Jerusalem to the Palestinians
But political analysts say that behind the bluster, Mr Barak is charting a more cautious route.
If Labour were to pull out of the governing coalition it could precipitate fresh national elections.
This is something that Labour party and the other members of the coalition do not want.
According to opinion polls, the opposition Likud party would be the big winner.
For now, the governing coalition will probably hold.
Instead, Mr Barak is expected to become the new defence minister, a job he has held before.
But he will also need to build Labour's support with the wider Israeli public if he is to win the next national election as he has stated.
It will not be an easy task.
When Mr Barak was prime minister from 1999-2001 he earned a reputation as being arrogant, high-handed and unprepared to listen to anyone other than himself.
He withdrew all Israeli forces from Lebanon in 2000 which was generally welcomed at the time. But following the war in Lebanon many Israelis have questioned the wisdom of such a move.
Mr Barak also infuriated many of his countrymen by offering East Jerusalem - but not all of the holy sites - to the Palestinians during the Camp David peace summit.
The talks between the Israelis and Palestinians ultimately broke down. But many Israelis believe that Mr Barak had been overly generous to the Palestinians.
Mr Barak insists that lessons have been learned - and that he is a changed man.
But many Israelis want to see Mr Barak's actions and not his words before they judge him.